Java根据身份证号计算年龄，15位身份证号码转18位原理与操作示例

package idcard;
import java.text.SimpleDateFormat;
import java.util.Date;
public class IdCardTest {
 //根据身份证号输出年龄
 public static int IdNOToAge(String IdNO){
  int leh = IdNO.length();
  String dates="";
  int age = 0;
  if (leh == 18) {
   dates = IdNO.substring(6, 10);
   SimpleDateFormat df = new SimpleDateFormat("yyyy");
   String year = df.format(new Date());
   age = Integer.parseInt(year)-Integer.parseInt(dates);
  }else {
   System.out.println("出错！身份证长度不是18位！");
  }
  return age;
 }
 public static void main(String[] args) {
  System.out.println(IdNOToAge("120000197802150561"));
  System.out.println(IdNOToAge("32000019951110538X"));
 }
}

package idcard;
import java.util.Scanner;
public class IDcard15bitTo18bit {
 public static String[] trans15bitTo18bit(String[] input){
  String[] result = new String[18];
  for(int i=0;i<input.length;i++){
   if(i<=5){
    result[i] = input[i];
   }else{
    result[i+2] = input[i];
   }
  }
  //年份最后两位小于17,年份为20XX，否则为19XX
  if(Integer.valueOf(input[6])<=1&&Integer.valueOf(input[7])<=7){
   result[6]="2";
   result[7]="0";
  }else{
   result[6]="1";
   result[7]="9";
  }
  //计算最后一位
  String[] xs = {"7","9","10","5","8","4","2","1","6","3","7","9","10","5","8","4","2"};
  //前十七位乘以系数[7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2],
  int sum = 0;
  for(int i=0;i<17;i++){
   sum+= Integer.valueOf(result[i]) * Integer.valueOf(xs[i]);
  }
  //对11求余，的余数 0 - 10
  int rod = sum % 11;
  //所得余数映射到对应数字即可
  if(rod==0){ result[17] = "1";
  }else if(rod==1){ result[17] = "0";
  }else if(rod==2){ result[17] = "X";
  }else if(rod==3){ result[17] = "9";
  }else if(rod==4){ result[17] = "8";
  }else if(rod==5){ result[17] = "7";
  }else if(rod==6){ result[17] = "6";
  }else if(rod==7){ result[17] = "5";
  }else if(rod==8){ result[17] = "4";
  }else if(rod==9){ result[17] = "3";
  }else if(rod==10){ result[17] = "2";}
  return result;
 }
 public static void main(String[] args) {
   //创建输入对象
   Scanner sc=new Scanner(System.in);
   //获取用户输入的字符串
   String str="";
   System.out.print("请输入您的15位身份证号：");
   str=sc.nextLine();
   System.out.println("您输入的15位身份证号为："+str);
   if(str.length()==15){
    String[] input = str.split("");
    String[] result = trans15bitTo18bit(input);
    System.out.print("您的18位身份证号是：");
    for(String c:result){
     System.out.print(c);
    }
   }else{
    System.out.println("不符合格式的身份证号！");
   }
 }
}

function ID15T18(strTemp)
{
var arrInt = new Array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);
var arrCh = new Array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'); 
var nTemp = 0, i;
if(strTemp.length==15)
{
strTemp = strTemp.substr(0,6) + '19' + strTemp.substr(6,strTemp.length-6);
for(i = 0; i < strTemp.length; i ++)
{
nTemp += strTemp.substr(i, 1) * arrInt[i];
}
strTemp += arrCh[nTemp % 11];
}
return strTemp;
}

privatestringConvert15To18(stringstrTemp)
{
int[]arrInt=newint[]{7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2};
stringarrCh="10X98765432";
intnTemp=0;
if(strTemp.Length==15)
{
strTemp=strTemp.Substring(0,6)+"19"+strTemp.Substring(6,strTemp.Length-6);
for(inti=0;i<strTemp.Length;i++)
{
nTemp+=int.Parse(strTemp.Substring(i,1).ToString())*arrInt[i];
}
strTemp+=arrCh[nTemp%11];
}
chardd=arrCh[nTemp%11];
returnstrTemp;
}